very short question(s) on blood magic and blood hunting

[onomastikon]

Hello,

experimenting with Pangaia Pandemoniac and blood, and am having trouble figuring out blood slaves.

Firstly, I get the message after 3 searches that the people will not tolerate another blood hunt. OK. Can I go back to a province after a break, or does that mean: cant ever search there again? If the latter -- how do I get enough Blood Slaves?

Secondly: "performing blood sacrifice" -- what apparently Mictlan and Abyssian priests can do -- what is that exactly, and is it the same as "perform blood hunt" or "use blood magic"?

Lastly: by sacrificing blood slaves, do they mean "using" them like gems?

thanks